Ransomware authors are not the only cybercriminals who use extortion tactics to make money from users and companies. Data thieves are also increasingly resorting to intimidation.

The FBI's Internet Crime Complaint Center (IC3) has received many reports from users whose data was stolen in various high-profile breaches and then received emails threatening to publicly disclose their personal information, including phone numbers, home addresses and credit card information.

The ransom amount asked by the extortionists ranged from 2 to 5 bitcoins or approximately $250 to $1,200, IC3 said in an advisory Wednesday.

In some cases, the attackers claim to have sensitive information about users' lives stolen from their online accounts and threaten to send it to their friends, employers and family.

"If you would like to prevent me from sharing this information with your friends and family members (and perhaps even your employers too) then you need to send the specified bitcoin payment to the following address," one email shared by the IC3 reads. "If you think this amount is too high, consider how expensive a divorce lawyer is. If you are already divorced then I suggest you think about how this information may impact any ongoing court proceedings. If you are no longer in a committed relationship then think about how this information may affect your social standing amongst family and friends."

It's not clear if the attackers actually have the information that they claim to have, but the extortion emails are typically sent shortly after high-profile data breaches. It's not hard to imagine that some users of compromised adult dating services would be willing to pay in order to avoid being associated with those sites.

"The FBI does not condone the payment of extortion demands as the funds will facilitate continued criminal activity, including potential organized crime activity and associated violent crimes," IC3 said.

In a separate report last week, security researchers from IBM warned that companies are also the target of extortion attempts by hackers who exploit vulnerabilities in their systems and steal data.

The attackers try to pass themselves as ethical bug hunters, even though the victim companies don't have bug bounty programs, and ask significant amounts of money to disclose the vulnerabilities that they exploited to obtain the data.

"While the attacker doesn’t explicitly threaten to release the data or attack the organization again, it leaves a lot of questions for the victims," the IBM researchers said.

In addition to ransomware, other forms of online extortion observed over the past year include asking for money under the threat of distributed denial-of-service (DDoS) attacks or stealing nude pictures, typically from women, and then asking them for more under the threat of making those pictures public -- an attack known as sextortion.